DETROIT -- The Tigers used their farm system a year ago to add the pieces they needed to make a World Series run, and they'll likely do the same to a lesser extent in the coming days before the July 31 non-waiver Trade Deadline. They know part of their job in player development is to mold prospects who become other teams' futures, while also helping the Tigers' present cause.

More than last year, however, the Tigers' present includes a big chunk of their future, as reflected in MLB.com's Midseason Top 20 Tigers prospect rankings.

While top prospect Nick Castellanos bides his time on the learning curve at Triple-A Toledo, Bruce Rondon's future is now. It wasn't as soon as team officials had hoped in Spring Training, when he was projected as the potential closer. Yet with each lead the young fastballer protects in the seventh and eighth, he looks more and more like a potential deciding factor in Detroit's bullpen down the stretch.

"I think Rondon comes as advertised," said Tigers closer Joaquin Benoit, who has mentored Rondon in his introduction to late-inning setup duty. "Everybody knows what he's capable of doing. You're not going to see that often -- a guy throwing 100 mph, and he's coming together."

While the Tigers continue trying to develop a shortstop of the future, they learned a lot about Hernan Perez, while he helped fill the void of second baseman Omar Infante when he was on the 15-day disabled list with a sprained ankle. Perez, meanwhile, jumped into the top 10 with one of the largest moves of anyone up the list.

"He's young, very talented and I think a terrific, terrific prospect," manager Jim Leyland said. "I really like him a lot, and I don't think he's far away."

While the Tigers continue to exercise patience on Avisail Garcia, giving him regular at-bats at Triple-A Toledo over a part-time role in Detroit to try to unlock the five-tool potential they see in him, he followed up his sensational September from last year's playoff drive by covering the Tigers in center field when Austin Jackson went on the disabled list last month. He picked up enough Major League time that he fell out of prospect status, but his potential impact in the Tigers outfield in the near future remains the same.

"This kid's a big-time prospect, and that's just what he is right now," Leyland said. "We love him. I said three or four years ago I thought he was the best prospect in the organization. He's got a chance to be the total package, because he can run, he can throw, he can hit -- and we think he's going to hit with power. He's a tools guy that's got a lot of tools."

It's not a system with as much depth as the Tigers might like, especially on the pitching side after trades over the last couple years sent young arms out for Major League-ready help. However, it arguably has more high-ceiling offensive talent and overall athleticism than it has in years, maybe the most since Dave Dombrowski took over as team president/general manager 11 years ago.

Graduated

Garcia's graduation from the prospect list is a product of big-league service time, not a big-league role. He became Detroit's right-handed hitting platoon outfielder of choice last September when trade acquisition Jeff Baker fizzled, then became their center field insurance for Jackson after the Tigers jettisoned Quintin Berry.

Garcia was the Tigers' third-ranked prospect going into the season, the high point of a steady rise that began with him on the fringe of the Tigers' top 10 rankings a year and a half ago. With each step along the developmental ladder, the 22-year-old has shown more polish to go with the athleticism that wowed scouts when he was a teenager in Venezuela.

When he sat on the bench as an extra player in Detroit last month, filling in while Matt Tuiasosopo was injured, that polish suffered along with his swing. Two days after he returned to Triple-A Toledo, he hit for the cycle, starting him on another tear at the plate for the Mud Hens.

"He's a freak, man," Tigers outfielder Matt Tuiasosopo said. "He's big, strong, fast. I was impressed in Spring Training when I saw him in the outfield."

Dropped off

Both Matt Hoffman and Kenny Faulk showed enough promise to earn invitations to big-league camp in recent years, giving them a chance to show Tigers coaches what they could bring as lefty relievers. Even though they aren't on the 40-man roster, they ranked 13th and 14th on the Tigers prospect list, respectively. Both fell off the midseason list.

Hoffman has stretches when he looks like a power lefty whose next logical step is the Majors, such as his 18 1/3-inning scoreless streak with 19 strikeouts from late April to mid-June. When he's off, the 24-year-old struggles with his command. Even so, he has more strikeouts than innings pitched in a season for the first time in his pro career, and he's stranding inherited baserunners at a better rate.

Faulk was an Eastern League All-Star last year at Double-A Erie, a pleasant surprise in Spring Training and a workhorse Mud Hens reliever in April with 9 1/3 scoreless innings and 15 strikeouts. A series of rough outings in May, however, preceded a stint on the disabled list with a broken hand.

Second baseman Jeff Kobernus dropped from the list because he changed organizations. He came to Spring Training as a Rule 5 Draft pick, trying to earn a utility role on the Tigers roster, but was sent back to the Nationals. He went from 16th on the Tigers prospect list to 10th on the Nationals.

New faces

Three of the four additions to the Tigers' Top 20 list are recent draft selections, headed by last month's top pick, Jonathon Crawford. The former University of Florida right-hander and current short-season Class A Connecticut reliever took over Garcia's old spot at No. 3 behind Castellanos and Rondon.

The Tigers' other first-round pick, former University of Texas closer Corey Knebel, vaulted to 17th on the list. The 21-year-old earned an aggressive placement to begin his pro career in the bullpen at low Class A West Michigan, where he has taken over closer duties. Detroit officials still view him as a potential starter, but decided to hold off on stretching out his arm.

Joining Crawford as a newcomer in the top 10 is right-hander Endrys Briceno, whose inconsistent season at West Michigan has shown flashes of what he can do with a mid-90s fastball when he commands it. His offspeed package is a work in progress. The 20-year-old Venezuelan had a strong stretch from late May into mid-June, but also had outings in which walks drained his pitch count.

Devon Travis didn't make last year's prospect list after the Tigers drafted him in the 13th round, but he has made a case as the best surprise in the system this year, checking in at No. 14. The former Florida State second baseman tore up the Midwest League for three months at West Michigan, batting .352 with a .430 on-base percentage and a .983 fielding percentage, before heading to high Class A Lakeland.

tigers' top prospects

Perez's aforementioned climb from 15th to 10th on the list tied him for the largest jump with right-hander Drew VerHagen, whose bump from 17th to 12th embodies his quick path through the Tigers farm system.

VerHagen went from fourth-round draft pick last summer to the rotation at Lakeland by summer's end, then moved up to Erie last month once Kyle Lobstein was promoted to Toledo. He tossed 17 scoreless innings of six-hit ball over back-to-back starts in July, including a complete-game three-hit shutout at Altoona.

The other Tigers prospect with a significant jump up the list was catcher James McCann, Detroit's top pick two years ago whose offensive emergence at Erie earned him a spot in the All-Star Futures Game in New York.

The largest fall down the list came from outfielder Tyler Collins, who went from Grapefruit League sensation in big-league camp to a feast-or-famine season at Erie. His July has shown results from midseason adjustments after he struck out 78 times in 281 at-bats over the season's first half.

Top 100 representation

The names are unchanged, only the rankings are different. Both Castellanos and Rondon jumped eight spots on MLB.com's Top 100 list to 13th and 84th, respectively. Castellanos overcame his early-season struggles at Toledo and his move to the outfield to reinforce his standing as one of the best pure hitters in any team's system. He is showing signs of maturing into some power as his 6-foot-4 frame fills out.

The Tigers continue to see more potential in Rondon than his rankings might suggest, though relievers sometimes have a hard time climbing the list compared with starting pitchers. Command has been the question with Rondon at each level and something he addressed at Triple-A Toledo during his time as Mud Hens closer.

With two players on the Top 100 list, the Tigers earned 105 "prospect points" -- points assigned to a club based on its representatives on the Top 100 list, with 100 points going to the team with the No. 1 prospect, 99 to the team with No. 2 and on down. Detroit fell out of the top 20, placing 21st in the Majors.

Jason Beck is a reporter for MLB.com. Read Beck's Blog and follow him on Twitter @beckjason. This story was not subject to the approval of Major League Baseball or its clubs.